DD6单晶冷却涡轮叶片模拟试样拉伸性能

研究了[001]取向的冷却叶片模拟试样的拉伸性能与断口。分别从温度、薄壁厚度以及气膜孔3个方面分析对其力学性能的影响。结果表明:薄壁圆管试样在过峰值温度后,抗拉强度与屈服强度随温度上升而降低,延伸率与截面收缩率则不断递增;2mm比1.5mm薄壁试样的抗拉强度、屈服强度、延伸率及截面收缩率都要大;带气膜孔试样存在应力应变集中,导致其抗拉强度与屈服强度,延伸率与截面收缩率都要比不带气膜孔试样的低。对试样断口进行SEM分析,结果表明在中温和高温条件下,断口呈现不同的断裂特点,850℃的试样断面由光滑斜平面组成,而980℃的断口则以韧窝断裂为主。

Tensile Property of a Modeling Specimen of DD6 Single Crystal Cooling Turbine Blade

Tensile properties and SEM analysis were carried out in a modeling specimen of cooling turbine blade with [001] orientation.Three factors including temperatures,thickness and cooling holes were considered to study the influences on the mechanics properties.The results show that when the temperature is higher than 850 ℃,the ultimate strength and yield strength decrease with the increment of temperature,while for the elongation and area reduction,they increase.Also,the ultimate strength and yield strength of the 2.0 mm thick specimens are higher than those of the 1.5 mm thick specimens,the same results for the elongation and area reduction.Because of the stress and strain concentrations,not only the ultimate strength and yield strength of the specimens with cooling holes are lower than those of specimens without cooling holes,but also for the percentages of elongation and area reduction.Furthermore,from the SEM analysis of the fracture faces,we conclude that at 850 ℃ the fracture surfaces are made up of smooth sloping planes,while at 980 ℃ the fracture surfaces are mainly made up of dimples.